Tailings slurries are suspensions in water of the fine-grained residues of the milling process by which raw materials are extracted from mined rock. Deposition of these slurries in ponds or lagoons, usually confined by man-made dams, can present serious safety and environmental risks, especially if there is inappropriate handling or management. In contrast thickened paste technology using very lowmoisture thickened tailings, has made rapid progress from 1995 onwards, and offers significant economic incentives and environmental benefits. No particle segregation takes place during the thickening process; the paste material exhibits much greater stability than conventional tailings; there is no need for a pond on top of the deposit; which itself forms a gently sloping surface which promotes runoff of rain water; and the overall costs are lower than for conventional slurry technologies.